This application claims priority of Taiwanese Application No. 091211223, filed on Jul. 23, 2002.
1. Field of the Invention
The present invention relates to a cutter unit, more particularly to a cutter unit for a wood planing machine.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional cutter unit for a wood planing machine is shown to include a rotating axle 13, a planing cutter 17, two positioning bars 14, and a forming cutter set.
As illustrated, the axle 13 includes an axle body 131 formed with an axially extending retaining groove 132 confined by a groove-confining wall 133W that has two opposing inclined wall portions 134, 135 and a bottom wall portion 133 interconnecting the inclined wall portions 134, 135. The planing cutter 17 is disposed within the retaining groove 132 in the axle body 131. The positioning bars 14 are disposed securely in the retaining groove 132 to press the planing cutter 17 against one of the inclined wall portions 134, 135 of the retaining groove 132 so as to prevent disengagement of the planing cutter 17 from the retaining groove 132. The positioning bars 14 respectively have opposing end faces 140 that are spaced apart from each other to define a cutter receiving chamber 132C therebetween. The forming cutter set is disposed in the cutter receiving chamber 132C, and includes a forming cutter 1 with a cutting edge 11, a cutter positioning block 15, and two fastener screws 16. The cutter positioning block 15 is disposed in the cutter receiving chamber 132C, and has two opposite end faces 151 respectively abutting against the opposing end faces 140 of the positioning bars 14, and two opposite inclined side faces 152, 153. The forming cutter 1 is disposed in the cutter receiving chamber 132C between the cutter positioning block 15 and the planing cutter 17. The fastener screws 16 extend respectively through two threaded holes 156 in the cutter positioning block 15, and are threadedly engaged within two threaded holes 136 in the bottom wall portion 133 of the groove-confining wall 133W, respectively, such that tightening of the fastener screws 16 results in an upward movement of the cutter positioning block 15 relative to the retaining groove 132, which, in turn, results in pressing of the forming cutter 1 against the planing cutter 17, thereby securing the forming cutter 1 in the cutter receiving chamber 132C.
Some disadvantages resulting from the use of the aforesaid conventional cutter unit are as follows:
(1) Since the forming cutter 1 is juxtaposed with the planing cutter 17, the user is exposed to injury during mounting and dismantling of the forming cutter 1 into and from the cutter receiving chamber 132C.
(2) During tightening operation of the fastener screws 16, the forming cutter 1 may wobble and move upwardly and downwardly in the cutter receiving chamber 132C, thereby resulting in an inaccurate positioning of the forming cutter 1 within the cutter receiving chamber 132C.
Therefore, the object of this invention is to provide a cutter unit for use in a wood planing machine, the cutter unit having a cutter positioning block by the use of which the aforementioned disadvantages can be avoided.
Accordingly, a cutter unit for a wood planing machine of the present invention includes: a rotating axle formed with an axially extending retaining groove confined by a groove-confining wall that has two opposing wall portions; two positioning bars mounted securely in the retaining groove and respectively having opposing end faces that are spaced apart from each other to define an axially extending cutter-receiving chamber therebetween; and a cutter set mounted detachably in the cutter-receiving chamber. The cutter set includes a cutter with two opposite end faces and two opposite abutting side faces, and a cutter positioning block having two opposite end faces respectively abutting against the opposing end faces of the positioning bars, and two opposite first and second side faces. The first side face of the cutter positioning block is indented to form a cutter-holding recess that receives the cutter therein and that is defined by a recess-confining wall with two opposing wall portions. The opposite end faces of the cutter respectively abut against the wall portions of the recess-confining wall of the cutter positioning block. One of the abutting side faces of the cutter is distal from the cutter positioning block, and is disposed outwardly of the cutter-holding recess. The other one of the abutting side faces of the cutter abuts against the recess-confining wall of the cutter positioning block. The cutter set further includes an adjusting unit that is disposed between and that abuts against the second side face of the cutter positioning block and one of the wall portions of the groove-confining wall of the retaining groove and that is adjustable to move the cutter positioning block and the cutter in a transverse direction relative to the wall portions of the groove-confining wall so as to press the one of the abutting side faces of the cutter against the other one of the wall portions of the groove-confining wall of the retaining groove, thereby securing the cutter in the cutter-receiving chamber.